Containment unit for cleaning a marine riser

ABSTRACT

Disclosed is a containment unit for cleaning a marine riser, that comprises a cylindrical containment tube adapted to fit over a flange at either end of the marine riser for collecting fluids from the marine riser during a cleaning operation; a first outlet adapted to attach to an underside of the cylindrical containment tube for directing the fluids to a waste storage when cleaning the marine riser at a higher level; an end plate adapted to attach to a first end of the cylindrical containment tube, wherein the end plate comprises an access hatch; and a second outlet adapted to attach to the end plate for directing the fluids to the waste storage when cleaning the marine riser at a lower level, wherein the access hatch enables access to the containment unit for cleaning the containment unit when the first outlet and the second outlet are blocked.

TECHNICAL FIELD

The present disclosure relates generally to a cleaning unit and more specifically, to a containment unit for cleaning a marine riser.

BACKGROUND

A marine riser is a conduit for transfer of drilling fluids to and from a drill bit to a platform or to a drilling rig. Moreover, the marine riser typically has a main riser tube that connects a subsea blowout preventer (BOP) stack to a floating surface rig to take waste returns to the surface drilling or production facility. The marine riser may include pipelines or flow-lines to transport materials such as produced hydrocarbons and auxiliary lines to control the BOP. The auxiliary lines may include two separate lines, with an internal diameter ranging from 2 inches to 4 inches for controlling a drilling well and the BOP. Typically, such lines are made of stainless-steel. The main riser tube has a large internal diameter that allows the passage of a drill string. Generally, the internal diameter of the main riser is about 18¾ inches. To maintain satisfactory operation, the marine riser must be cleaned periodically to remove waste or debris that gets accumulated inside it. The cleaning of the marine riser is usually performed when the marine riser is placed on a deck of the drilling rig in designated bays or sent ashore for cleaning.

Traditionally, marine risers are cleaned using high pressure or ultra-high-pressure water jets. The high-pressure water washing is performed at a pressure in a range of 1,000 pound per square inch (psi) (6, 894, 757 Pascal) to 10,000 psi (68, 947, 573 Pascal). The high-pressure water jets blast water at a pressure in a range of 10,000 pound per square inch (psi) (68, 947, 573 Pascal) to 25,000 psi (172, 368, 932 Pascal) using their rotating heads, to clean the accumulated solid waste or debris. Moreover, the ultra-high-pressure water jets blast water at a pressure in a range of 25,000 psi (172, 368, 932 Pascal) to 40,000 psi (275, 790, 292 Pascal) using their rotating heads, to clean the accumulated solid waste or debris. The high-pressure washing may not effectively clean the marine riser. Sometimes, if not contained, the solid waste or debris may spill on the deck or quayside or in the ocean while cleaning the marine riser.

Another existing method for cleaning a pipe of the marine riser uses a pressured air supply, which is connected to one end of a vibrating tool with a brush that is inserted into the pipe that is to be cleaned. The tool imparts vibration to the brush that causes the tool to work its way along the length of the pipe to be cleaned. When the tool has reached a far end of the pipe, the direction of the brush bristle changes, causing the tool to work its way back along the pipe to an operator operating the tool. Alternatively, the air supply is turned off and the tool is retrieved, or manually turned around. The tool is operated with a specialized motor to move the brush both forward and backward for cleaning the marine riser. However, the brush gets clogged when the solid wastes or debris are wet and heavy. This causes the brush to stop operating or functioning while cleaning the marine riser. Furthermore, on account of the marine riser's large size and length, it is often difficult to pull the brush back into the pipe or retrieve it manually.

Therefore, in light of the foregoing discussion, there exists a need to address the aforementioned drawbacks in existing approaches due to their inability to clean the marine riser completely, spilling of the solid waste and debris on the deck or quayside or in the ocean while cleaning the marine riser and a difficulty in pulling back the cleaning brush from the pipe of the marine riser.

SUMMARY

The present disclosure provides a containment unit for cleaning a marine riser, comprising:

-   -   a cylindrical containment tube adapted to fit over a flange at         either end of the marine riser for collecting fluids from the         marine riser during a cleaning operation;     -   a first outlet adapted to attach to an underside of the         cylindrical containment tube for directing the fluids to a waste         storage when cleaning the marine riser at a higher level;     -   an end plate adapted to attach to a first end of the cylindrical         containment tube, wherein the end plate comprises an access         hatch; and     -   a second outlet adapted to attach to the end plate for directing         the fluids to the waste storage when cleaning the marine riser         at a lower level, wherein the access hatch enables access to the         containment unit for cleaning the containment unit when the         first outlet and the second outlet are blocked.

The present disclosure also provides a system comprising:

-   -   a marine riser; and     -   a containment unit operable to attach to the marine riser for         cleaning the marine riser, comprising         -   a cylindrical containment tube adapted to fit over a flange             at either end of the marine riser for collecting fluids from             the marine riser during a cleaning operation;         -   a first outlet adapted to attach to an underside of the             cylindrical containment tube for directing the fluids to a             waste storage when cleaning the marine riser at a higher             level;         -   an end plate adapted to attach to a first end of the             cylindrical containment tube, wherein the end plate             comprises an access hatch; and         -   a second outlet adapted to attach to the end plate for             directing the fluids to the waste storage when cleaning the             marine riser at a lower level, wherein the access hatch             enables access to the containment unit for cleaning the             containment unit when the first outlet and the second outlet             are blocked.

The present disclosure further provides a method of assembling a containment unit to a marine riser for cleaning the marine riser, comprising:

-   -   fitting a cylindrical containment tube over a flange at either         end of the marine riser for collecting fluids from the marine         riser during a cleaning operation;     -   attaching a first outlet to an underside of the cylindrical         containment tube for directing the fluids to a waste storage         when cleaning the marine riser at a higher level;     -   attaching an end plate to a first end of the cylindrical         containment tube;     -   attaching a second outlet to the end plate for directing the         fluids to the waste storage when cleaning the marine riser at a         lower level; and     -   enabling access to the containment unit for cleaning the         containment unit through an access hatch on the end plate when         the first outlet and the second outlet are blocked.

Embodiments of the present disclosure substantially eliminate or at least partially address the aforementioned problems in the prior art due to their inability to clean the marine riser completely, spilling of the solid waste and debris on the deck or quayside or in the ocean while cleaning the marine riser and a difficulty in pulling back the cleaning brush from the pipe of the marine riser. For example, the present disclosure substantially eliminates or at least partially addresses the difficulty found with brush type systems, i.e. they struggle to clean wet or damp debris and push the accumulated deposits through the marine riser (which causes the brushes to stop) when marine riser lengths exceed 65 feet.

Additional aspects, advantages, features and objects of the present disclosure are made apparent from the drawings and the detailed description of the illustrative embodiments construed in conjunction with the appended claims that follow.

It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.

Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:

FIG. 1 is a left side view of a containment unit in accordance with an embodiment of the present disclosure;

FIG. 2 is a front view of a containment unit in accordance with an embodiment of the present disclosure;

FIG. 3 is a perspective view of a containment unit in accordance with an embodiment of the present disclosure;

FIG. 4 is a perspective view of a containment unit that comprises a removable flange adapter in accordance with an embodiment of the present disclosure;

FIG. 5 is a front view of a removable flange adapter of a containment unit in accordance with an embodiment of the present disclosure;

FIG. 6 is a left side cross sectional view of a cylindrical containment tube in accordance with an embodiment of the present disclosure;

FIG. 7 is a front view of a containment unit in accordance with an embodiment of the present disclosure;

FIG. 8 is a schematic illustration of a system in accordance with an embodiment of the present disclosure; and

FIG. 9 is a flow diagram illustrating a method of assembling a containment unit to a marine riser for cleaning the marine riser in accordance with an embodiment of the present disclosure.

In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

DETAILED DESCRIPTION OF EMBODIMENTS

The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.

The present disclosure provides a containment unit for cleaning a marine riser, comprising:

-   -   a cylindrical containment tube adapted to fit over a flange at         either end of the marine riser for collecting fluids from the         marine riser during a cleaning operation;     -   a first outlet adapted to attach to an underside of the         cylindrical containment tube for directing the fluids to a waste         storage when cleaning the marine riser at a higher level;     -   an end plate adapted to attach to a first end of the cylindrical         containment tube, wherein the end plate comprises an access         hatch; and     -   a second outlet adapted to attach to the end plate for directing         the fluids to the waste storage when cleaning the marine riser         at a lower level, wherein the access hatch enables access to the         containment unit for cleaning the containment unit when the         first outlet and the second outlet are blocked.

The containment unit is a portable unit that collects the fluids (e.g. oil residues, mud, drilling fluids chemical deposits etc.) from the marine riser during the cleaning operation, thus increasing efficiency of the marine riser and reducing time consumption for cleaning the marine riser. The containment unit collects the fluids (e.g. waste fluids) from the marine riser during the cleaning operation and enables the fluids to be drained or pumped from the marine riser. The waste storage may be an environmentally friendly waste storage. The containment unit ensures that the waste fluids are completely collected from the marine riser on a deck, or if done ashore, on a dockside. The containment unit is relatively simple in design and easily fitted to the flange at either end of the marine riser. The containment unit is designed to eliminate any discharge of the fluids and create 100% containment. In an embodiment the containment unit is used in conjunction with the marine riser during the cleaning operation for collecting the fluids from the marine riser while cleaning.

In an embodiment a thickness of the cylindrical containment tube ranges from 4 millimetres (mm) to 6 mm, an outer diameter of the cylindrical containment tube is 1190 mm, an internal diameter of the cylindrical containment tube is 1090 mm and a length of the cylindrical containment tube is 500 mm. In another embodiment a size of the cylindrical containment tube varies according to a type of the marine riser to be cleaned. The cylindrical containment tube may be rolled to a predetermined diameter (e.g. based on an internal diameter of the marine riser) to fit over the flange at either end of the marine riser.

The fluids or wastage from the marine riser are collected in the containment unit and are directed to the waste storage through the first outlet (e.g. bottom outlet) when cleaning the marine riser at higher levels (e.g. at different heights). In an embodiment more than one outlet may be attached to the underside of the cylindrical containment tube for directing the fluids to the waste storage when cleaning the marine riser at the higher levels. The fluids may be directed to the waste storage via the second outlet when cleaning the marine riser at lower levels (e.g. yard or deck level). In an embodiment more than one outlet may be attached with the end plate for directing the fluids to the waste storage when cleaning the marine riser at the lower levels.

The first end of the cylindrical containment tube may be plated to form the end plate. In an embodiment the end plate is welded to the cylindrical containment tube. The end plate may direct the fluids from the marine riser to the first outlet and the second outlet. The access hatch may provide an opening to access the first outlet and the second outlet. A shape of the access hatch may be circular, oval, elliptical, oblong, semi-circular or any other shape suitable to the containment unit. The access hatch may enable access to an interior part of the containment unit for cleaning. In an embodiment a radius of the access hatch is 400 mm.

The containment unit may include a lifting lug that is adapted to lift the containment unit. For example, the lifting lug is fitted to the outer diameter of the cylinder in a position to allow the containment unit to be lifted in a vertical position and on a balanced plane. The containment unit may include a handle to pull or push the containment unit.

The containment unit may include a gasket that is adapted to attach to the second end of the cylindrical containment tube. In an embodiment the gasket is fitted to the end plate of the cylindrical containment tube. The gasket may be made of neoprene, rubber, paper, silicone, metal, cork, felt nitrile rubber, fiberglass, polytetrafluoroethylene, plastic polymer or any other suitable material.

In an embodiment the marine riser is cleaned using a high pressure or an ultra-high-pressure water jet. The high pressure (UH) or the ultra-high pressure (UPH) water jet comprises a cleaning nozzle (e.g. rotating nozzle). The high-pressure cleaning nozzle or the ultra-high pressure cleaning nozzle is passed into lines of the marine riser to clean the marine riser internally and wash the fluids ahead of the high pressure cleaning nozzle and the ultra-high pressure cleaning nozzle towards the containment unit and allowing the containment unit to channel the waste fluids to the waste storage.

According to an embodiment the lower level is a level of height ranging from 1 to 4 meters from a deck, wherein the higher level is a level of height that is above the lower level. According to another embodiment the higher-level ranges from 5 meters to 20 meters from the deck.

In other words, the “lower level” is meant by a height up to a first row of marine risers when the marine risers are stacked on top of each other at the deck for cleaning. The “lower level” is also meant by a height up to a maximum of 1 to 3 rows of the marine risers when stacking on top of each other at the deck. The “higher level” is meant by a height that is above 4 meters from the deck. In other words, the higher level is meant by a height that is above a first three rows of the marine risers when stacking on top of each other at the deck.

According to yet another embodiment the containment unit further comprises an access cover removably attached to the access hatch for cleaning the first outlet and the second outlet via the access hatch when the access cover is in an open position.

In one embodiment the access cover is removably attached with the end plate using bolts, screws etc. The access cover may be removed from the end plate to provide access to the access hatch and to clean the containment unit when the first outlet and the second outlet are blocked. The interior part of the containment unit may also be cleaned after the access cover is removed from the end plate.

According to yet another embodiment the containment unit further comprises a removable flange adapter removably attached to a second end of the cylindrical containment tube, wherein the removable flange adapter is adapted to fit with the flange of the marine riser. The removable flange adapter may be suitable for different marine risers. For example, the removable flange adapter may be configured to fit and adapt to Cameron Load King riser. A size and a thickness of the removable flange adapter may be designed based on a size and thickness of the flange. A size of the containment unit may also vary due to difference in the size of the flange. In an embodiment a diameter of the removable flange adapter is 1185 mm. The removable flange adapter plate is used to cover and bolt the holes in the flange of the marine riser.

According to yet another embodiment the cylindrical containment tube is adapted to fully seal an internal void of a main tube and one or more auxiliary lines of the marine riser for collecting the fluids from the marine riser. The cylindrical containment tube may fully seal either end of the marine riser at an offshore location to allow for an ultra-high-pressure cleaning or a high-pressure cleaning (e.g. hydroblast or waterblast cleaning etc.). In an embodiment the containment unit includes a lever arm that locks the containment unit with the marine riser to effectively seal the internal voids of the main tube and the one or more auxiliary lines of the marine riser and collect any surplus fluids that are generated. Furthermore, the spray from these rotating nozzles is stopped by the rubber curtains.

According to yet another embodiment the containment unit further comprises a camlock fitting coupled to each outlet for draining the fluids from the containment unit. The camlock fitting may be fitted on the underside of the containment unit when cleaning the marine riser at the higher levels for draining the waste fluids collected from the containment unit. The camlock fitting may be used to rapidly connect and/or disconnect external fittings on the first outlet and the second outlet. The camlock fitting may be made of Aluminium.

According to yet another embodiment the containment unit further comprises one or more pins operable to attach to an exterior of the cylindrical containment tube for clamping the containment unit to the flange of the marine riser. The one or more pins may comprise latching points for clamping the containment unit to the flange of the marine riser. The one or more pins may be designed based on a depth and a size of the flange of the marine riser. This type of clamping is one of the several designs that may be used to clamp the containment unit to the flange of the marine riser to effectively seal the internal voids of the main tube and the one or more auxiliary lines of the marine riser.

According to yet another embodiment the containment unit comprises a diaphragm pump attached in operation to each outlet wherein the diaphragm pump is connected in series to the outlets for discharging the fluids to the waste storage. The diaphragm pump may be attached in operation to the first outlet for discharging the fluids to the waste storage when cleaning the marine riser at the higher level. The diaphragm pump may be attached in operation to the second outlet for discharging the fluids to the waste storage when cleaning the marine riser at the lower level. In an embodiment the containment unit may include any other suitable pump that is attached to each outlet for discharging the fluids to the waste storage.

The present disclosure also provides a system comprising:

-   -   a marine riser; and     -   a containment unit operable to attach to the marine riser for         cleaning the marine riser, comprising         -   a cylindrical containment tube adapted to fit over a flange             at either end of the marine riser for collecting fluids from             the marine riser during a cleaning operation;         -   a first outlet adapted to attach to an underside of the             cylindrical containment tube for directing the fluids to a             waste storage when cleaning the marine riser at a higher             level;         -   an end plate adapted to attach to a first end of the             cylindrical containment tube, wherein the end plate             comprises an access hatch; and         -   a second outlet adapted to attach to the end plate for             directing the fluids to the waste storage when cleaning the             marine riser at a lower level, wherein the access hatch             enables access to the containment unit for cleaning the             containment unit when the first outlet and the second outlet             are blocked.

According to an embodiment the containment unit comprises an access cover removably attached to the access hatch for cleaning the first outlet and the second outlet via the access hatch when the access cover is in an open position.

According to another embodiment the containment unit comprises a removable flange adapter that is removably attached to a second end of the cylindrical containment tube, wherein the removable flange adapter is adapted to fit with the flange of the marine riser.

According to yet another embodiment the cylindrical containment tube is made of Aluminium. The cylindrical containment tube may be made of any other suitable material that can withstand high pressure and is less in weight.

The advantages of the present system are thus identical to those disclosed above in connection with the present containment unit and the embodiments listed above in connection with the containment unit apply mutatis mutandis to the system.

The present disclosure further discloses a method of assembling a containment unit to a marine riser for cleaning the marine riser, comprising:

-   -   fitting a cylindrical containment tube over a flange at either         end of the marine riser for collecting fluids from the marine         riser during a cleaning operation;     -   attaching a first outlet to an underside of the cylindrical         containment tube for directing the fluids to a waste storage         when cleaning the marine riser at a higher level;     -   attaching an end plate to a first end of the cylindrical         containment tube;     -   attaching a second outlet to the end plate for directing the         fluids to the waste storage when cleaning the marine riser at a         lower level; and     -   enabling access to the containment unit for cleaning the         containment unit through an access hatch on the end plate when         the first outlet and the second outlet are blocked.

According to an embodiment the method further comprises removably attaching an access cover to the access hatch for cleaning the first outlet and the second outlet via the access hatch when the access cover is in an open position.

The advantages of the present method are thus identical to those disclosed above in connection with the present containment unit and the embodiments listed above in connection with the containment unit apply mutatis mutandis to the method.

Embodiments of the present disclosure may collect the fluids (e.g. waste fluids) completely from the marine riser during the cleaning operation. The embodiments of the present disclosure may fit the containment unit to either end of the offshore marine riser and seal the end of the marine riser to allow an ultra-high pressure cleaning or a high pressure cleaning. Further, the embodiments of the present disclosure may collect the waste fluids from the marine riser and channel the waste fluids to the environmental friendly waste storage or a secure tank, thereby preventing the waste fluids spills into the deck or quayside or in the ocean. The embodiments of the present disclosure may be used to contain any other form of cleaning that would be using air, seawater or cleaning fluid in the main bore and the auxiliary lines of the marine riser. The embodiments of the present disclosure may capture and contain all waste fluids and contaminants created from the cleaning of subsea marine riser joints. The embodiments of the present disclosure effectively clean the marine riser on board (e.g. on the deck) and preferably in the bays, and thereby reducing the cost of transporting the marine riser to quayside facilities for cleaning.

The aforementioned high pressure pertains to a pressure in a range of 10,000 pound per square inch (psi) (68, 947, 573 Pascal) to 25,000 psi (172, 368, 932 Pascal). Moreover, the aforementioned ultra-high pressure pertains to a pressure in a range of 25,000 psi (172, 368, 932 Pascal) to 40,000 psi (275, 790, 292 Pascal).

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a left side view of a containment unit in accordance with an embodiment of the present disclosure. The containment unit comprises a cylindrical containment tube 102, a first outlet 104, an end plate 106 and a second outlet 108. The functions of these parts are as have been described above.

FIG. 2 is a front view of a containment unit in accordance with an embodiment of the present disclosure. The containment unit comprises a cylindrical containment tube 202, a first outlet 204, an end plate 206, a second outlet 208, one or more pins 210, a lifting lug 212, an access hatch 214 and an access cover 216. The functions of these parts are as have been described above.

FIG. 3 is a perspective view of a containment unit in accordance with an embodiment of the present disclosure. The containment unit comprises a cylindrical containment tube 302, a first outlet 304, an end plate 306, a second outlet 308, one or more pins 310, a lifting lug 312 and an access hatch 314. The functions of these parts are as have been described above.

FIG. 4 is a perspective view of a containment unit that comprises a removable flange adapter 402 in accordance with an embodiment of the present disclosure. The containment unit further comprises a cylindrical containment tube 404, one or more pins 406 and a camlock fitting 408. The functions of these parts are as have been described above.

FIG. 5 is a front view of a removable flange adapter 502 of a containment unit in accordance with an embodiment of the present disclosure. The removable flange adapter 502 is removably attached to a second end of a cylindrical containment tube. The functions of the removable flange adapter 502 are as have been described above.

FIG. 6 is a left side cross sectional view of a cylindrical containment tube 602 in accordance with an embodiment of the present disclosure. The cylindrical containment tube 602 may be rolled to a predetermined diameter to fit over a flange of a marine riser. The functions of the cylindrical containment tube 602 are as have been described above.

FIG. 7 is a front view of a containment unit in accordance with an embodiment of the present disclosure. The containment unit comprises a cylindrical containment tube 702 and a lever arm 704. The cylindrical containment tube 702 may be made up of Aluminium. The functions of the cylindrical containment tube 702 and the lever arm 704 are as have been described above.

FIG. 8 is a schematic illustration of a system in accordance with an embodiment of the present disclosure. The system comprises a marine riser 802 and a containment unit 804. The containment unit 804 is attached to the marine riser 802 for collecting fluids (e.g. waste fluids) while cleaning the marine riser 802. The functions of these parts are as have been described above.

FIG. 9 is a flow diagram illustrating a method of assembling a containment unit to a marine riser for cleaning the marine riser in accordance with an embodiment of the present disclosure. At a step 902, a cylindrical containment tube is fitted over a flange at either end of the marine riser for collecting fluids from the marine riser during a cleaning operation. At a step 904, a first outlet is attached to an underside of the cylindrical containment tube for directing the fluids to a waste storage when cleaning the marine riser at a higher level. At a step 906, an end plate is attached to a first end of the cylindrical containment tube. At a step 908, a second outlet is attached to the end plate for directing the fluids to the waste storage when cleaning the marine riser at a lower level. At a step 910, an access to the containment unit is enabled for cleaning the containment unit through an access hatch on the end plate when the first outlet and the second outlet are blocked.

Modifications to embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. 

1. A containment unit for cleaning a marine riser, comprising: a cylindrical containment tube adapted to fit over a flange at either end of the marine riser for collecting fluids from the marine riser during a cleaning operation; a first outlet adapted to attach to an underside of the cylindrical containment tube for directing the fluids to a waste storage when cleaning the marine riser at a higher level; an end plate adapted to attach to a first end of the cylindrical containment tube, wherein the end plate comprises an access hatch; and a second outlet adapted to attach to the end plate for directing the fluids to the waste storage when cleaning the marine riser at a lower level, wherein the access hatch enables access to the containment unit for cleaning the containment unit when the first outlet and the second outlet are blocked.
 2. The containment unit according to claim 1, wherein the lower level is a level of height ranging from 1 to 4 meters from a deck, wherein the higher level is a level of height that is above the lower level.
 3. The containment unit according to claim 2, wherein the higher level ranges from 5 meters to 20 meters from the deck.
 4. The containment unit according to claim 1, further comprising an access cover removably attached to the access hatch for cleaning the first outlet and the second outlet via the access hatch when the access cover is in an open position.
 5. The containment unit according to claim 1, further comprising a removable flange adapter removably attached to a second end of the cylindrical containment tube, wherein the removable flange adapter is adapted to fit with the flange of the marine riser.
 6. The containment unit according to claim 1, wherein the cylindrical containment tube is adapted to fully seal an internal void of a main tube and one or more auxiliary lines of the marine riser for collecting the fluids from the marine riser.
 7. The containment unit according to claim 1, further comprising a camlock fitting coupled to the first outlet and the second outlet for draining the fluids from the containment unit.
 8. The containment unit according to claim 1, further comprising one or more pins operable to attach to an exterior of the cylindrical containment tube for clamping the containment unit to the flange of the marine riser.
 9. The containment unit according to claim 1, comprising a diaphragm pump that is attached in operation to and connected in series with the first outlet and the second outlet, for discharging the fluids to the waste storage.
 10. A system comprising: a marine riser; and a containment unit operable to attach to the marine riser for cleaning the marine riser, comprising a cylindrical containment tube adapted to fit over a flange at either end of the marine riser for collecting fluids from the marine riser during a cleaning operation; a first outlet adapted to attach to an underside of the cylindrical containment tube for directing the fluids to a waste storage when cleaning the marine riser at a higher level; an end plate adapted to attach to a first end of the cylindrical containment tube, wherein the end plate comprises an access hatch; and a second outlet adapted to attach to the end plate for directing the fluids to the waste storage when cleaning the marine riser at a lower level, wherein the access hatch enables access to the containment unit for cleaning the containment unit when the first outlet and the second outlet are blocked.
 11. The system according to claim 10, wherein the containment unit comprises an access cover removably attached to the access hatch for cleaning the first outlet and the second outlet via the access hatch when the access cover is in an open position.
 12. The system according to claim 10, wherein the containment unit comprises a removable flange adapter that is removably attached to a second end of the cylindrical containment tube, wherein the removable flange adapter is adapted to fit with the flange of the marine riser.
 13. The system according to claim 10, wherein the cylindrical containment tube is made of Aluminium.
 14. A method of assembling a containment unit to a marine riser for cleaning the marine riser, comprising: fitting a cylindrical containment tube over a flange at either end of the marine riser for collecting fluids from the marine riser during a cleaning operation; attaching a first outlet to an underside of the cylindrical containment tube for directing the fluids to a waste storage when cleaning the marine riser at a higher level; attaching an end plate to a first end of the cylindrical containment tube; attaching a second outlet to the end plate for directing the fluids to the waste storage when cleaning the marine riser at a lower level; and enabling access to the containment unit for cleaning the containment unit through an access hatch on the end plate when the first outlet and the second outlet are blocked.
 15. The method according to claim 14, further comprising removably attaching an access cover to the access hatch for cleaning the first outlet and the second outlet via the access hatch when the access cover is in an open position. 16-20. (canceled) 